Pinning Down Gravitational Settling
Astrophysics
2015-06-24 v1
Abstract
We analyse high-resolution archival UVES data of turnoff and subgiant stars in the nearby globular cluster NGC 6397 ([Fe/H] = -2). Balmer-profile analyses are performed to derive reddening-free effective temperatures. Due to the limited S/N and uncertainties related to blaze removal, we find the data quality insufficient to exclude the existence of gravitational settling. If the newly derived effective temperatures are taken as a basis for an abundance analysis, the photospheric iron (Fe II) abundance in the turnoff stars is 0.11 dex lower than in the (well-mixed) subgiants.
Keywords
Cite
@article{arxiv.astro-ph/0608338,
title = {Pinning Down Gravitational Settling},
author = {Andreas J. Korn and Nikolai Piskunov and Frank Grundahl and Paul Barklem and Bengt Gustafsson},
journal= {arXiv preprint arXiv:astro-ph/0608338},
year = {2015}
}
Comments
4 pages, 3 figures. Summary of a talk given at the ESO-Arcetri workshop in September of 2004. See also astro-ph/0608201